Transmission



Oct. 23, 1962 H. w. CHRIS'ILENSON 3,059,746

TRANSMISSION 3 Sheets-Sheet 1 Original Filed Jan. 26, 1955 INVENT RHOWARD WCHKLS 7 EA/SON ATTORNEY Oct. 23, 1962 H. w. CHRISTENSON3,059,746

TRANSMISSION Original Filed Jan. 26, 1955 3 Sheets-Sheet 2 1 INVENTORHOWARD W CHRIS TE/VSO/V ATTORNEY Oct. 23, 1 2 H. w. CHRISTENSON3,059,746

TRANSMISSION Original Filed Jan. 26, 1955 3 Sheets-Sheet 3 INVENTORWCHRZSfEA/SOA/ Q. 2 Mui AT TORNEV United States Patent O 3,059,746TRANSMISSION Howard W. Christenson, Indianapolis, Ind., assignor toGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareOriginal application Jan. 26, 1955, Ser. No. 484,122. Di-

vided and this application July 23, 1959, Ser. No. 829,139

19 Claims. (Cl. 19287) This invention relates to automatic transmissionsand more particularly to transmission steering clutches and a controlsystem for steering clutches. This application is a division of parentapplication S.N. 484,122, filed January 26, 1955, now Patent No.2,930,257.

The engine is connected by means of either the torque converter or thedirect drive lockup clutch to the three speed and reverse planetary geartransmission. The output shaft of the transmission is connected by abevel gear set to the cross drive shaft. The cross drive shaft. Thecross drive shaft drives the ring gear of a planetary gear set locatedat each side of the vehicle. These two planetary gear sets provide thedouble differential drive and include pinions meshing with the ring gearand a sun gear. The pinions are mounted on a carrier connected to theintermediate output shaft which drives the propulsion members. Thereaction of this double differential is provided through the sun gear ineach differential gear set and a :drive interconnection between the sungears to provide the normal differential type drive. The torqueconverter or the direct drive clutch output shaft extends through thetransmission and provides both a transmission input and a steer drivewhich is transmitted through a gear connection to the steer drive shaft.The steer drive shaft is connected via the right and the left steerclutches to the torque reaction sun gears of the differential on eachside of the vehicle. The double differential drives an intermediateoutput shaft which has mounted thereon a multiple disc type brake anddrives the sun gear of the planetary reduction gear. The pinions on theoutput are connected by the output shaft to the propulsion memberdriving the vehicle.

The multiple plate steer clutch is located in the double differentialhousing and connects the sun gear of the double differential to the spurgear driven by the steer shaft. The clutch is actuated by a hydraulicservo motor having a stationary annular piston acting through a ballbearing transfer hearing. A spool valve, fixed to move with the annularpiston, admits a very small quantity of oil to lubricate the steeringclutch when the clutch is disengaged and admits a large quantity oflubricant to the steering clutch to cool the clutch plates when theclutch is engaged. The hydraulic control system for the transmission,the torque converter and the steering clutches, have a fluid supplycomposed of engine and output shaft driven pumps. A first pressureregulator valve supplies a low pressure for intermediate and high ratiocontrol and a higher pressure for low and reverse ratio control.Thereafter a series of pressure regulator valves provides sequentiallyfurther reduced pressures for the steering clutch system, the torqueconverter and the lubricating system. The steering clutch controlemploys a pair of valves which are simultaneously moved in oppositedirections by a single control lever to admit operating fluid to eithersteer clutch servo. The vehicle operator can feel the extent of pressurebeing applied to the steer clutch servo on the control handle for thesteering valves since the steering valves are cross-connected so thatthe clutch apply pressure opposes the movement of one steering valve andassists the movement of the other steering valve.

An object of the invention is to provide in an automatic 3,059,746Patented Oct. 23, 1962 transmission steering control arrangement, a pairof steering valves connected to the right and left hand steeringclutches and arranged to be actuated by a single control lever, ahydraulic reaction force acting on the valves and arranged to oppose themovement of one valve and to assist the movement of the other valve ofthe steering system.

- Another object of the invention is to provide in a steering clutchassembly, a steering clutch cooling and lubricating system wherein thecontrol valve provides a small flow of lubricating oil when the clutchis released and a large fiow of cooling oil when the clutch is applied.

Another object of the invention is to provide a compact structuralarrangement of a clutch and the controlled and controlling elementsassociated therewith and the hydraulic actuating motor.

These and other objects of the invention will be more apparent from thefollowing description and drawing of a preferred embodiment of theinvention.

FIG. 1 is a diagrammatic view of the transmission including the torqueconverter, the planetary ratio gearing and the double differentialsteering drive.

FIG. 2 is a sectional view of the differential and steering clutch withparts broken away and in section to show details.

FIG. 3 is a schematic view of the hydraulic control systern for theconverter and steering system.

Referring to the drawing, FIG. 1 shows a diagrammatic view of thetransmission gearing. The engine drive shaft is connected to a couplingflange 10 on the converter input shaft 111 which drives the torqueconverter housing 12. The impeller blades 13 are mounted within thetorque converter housing 12 and hydrokinetically drive the turbine 14which is mounted on a drive disc 15 connected to the torque converteroutput shaft 16. The first stator 17 and the second stator 18 areconnected in the usual way through one-way brakes to the sleeve portionof the housing '19. The fixed clutch driving disc 21 is mounted on thetorque converter housing 12 and the movable annular plate 22, whichserves as a clutch driving disc and as a piston, is mounted for axialsliding movement on the shaft 16. The'clutchdriven plate 23 is mountedon the drive disc 15 on output shaft 16. When fluid is admitted underpressure to the space between the front wall of the torque converterhousing 12 and the annular plate 22, the plate 22 acts as a piston andmoves until the clutch plate portion ofthe plate 22 engages the clutchdriven plate 23 to provide a direct drive between the input shaft 11 andthe torque converter output shaft 16. An accessory drive gear 26 ismounted at the rear of the torque converter housing .12 and drives,through spur gears 27, 28 and 29, an accessory drive shaft 30 for'theengine driven pumps, a power take-off shaft or other accessory which itis desired to connect to the engine.

The torque converter output shaft 16 is directly connected to the inputgears, a small sun gear 37 and the large sun gear 38, of the three ratioand reverse planetary transmission unit. The small or low ratio sun gear37 meshes with the planetary pinion 39 mounted on the carrier 40 and theplanetary pinion meshes with a ring gear 41 on a carrier element 42.Ground clutch or brake 43 is applied to stop the carrier element 42 andthe ring gear 41 thereon in order to provide low speed drive through/thecarrier element 40, the sleeve shaft 46 and the output bevel gear 47.The large or intermediate ratio sun gear 38 meshes with the planetarypinion 51 mounted on the carrier 42. The planetary pinion 51 also mesheswith the ring gear 52 which is controlled by the intermediate brake 53.The high speed clutch 55 has a driving element 56 connected tothe torqueconverter output shaft 16 and a driven element connected to the ringgear 52. The reverse planetary gear unit has a sun gear 58 mounted onplanetary carrier 42 which meshes with the planetary pinion 59 mountedon a carrier 63 attached to the output bevel gear 47. A ring gear 60meshes with the planetary gear 59 and is controlled by the reverse brake61.

This transmission provides three forward speed ratios and reverse byindividually actuating one servo motor to engage one of the frictionclutches or brakes at a time. When the low brake is engaged, the carrier42 and the associated ring gear 41 is held stationary and the sun gear'37 drives the planet gear 39 which is connected to the output gear 47at the reduced speed. In intermediate speed, the brake 53 is applied tostop the ring gear 52 and provide a double planetary intermediate gear.When the ring gear 52 is stationary, the sun gear 38 drives theplanetary pinion 51 to rotate the ring gear 41 and the planetary carrier42 at a reduced speed. Since the carrier 42 and its associated ring gear41 is rotating, the drive from the sun gear 37 to the planetary pinion39 is at a slightly increased speed, compared to the low ratio and theplanetary pinion 39 is similarly connected by the carrier 40 and shaft46 to the output bevel gear 47. High gear is provided by engaging thehigh clutch 55 to connect the input shaft 16 through the plate 56 to thering gear 52. Since the ring gear 52 and the sun gear 38 of theintermediate planetary gear set are connected to the input shaft, thisplanetary gear set and the entire dual planetary gear set are locked andthe carrier 40 and sleeve shaft 46 drive the output bevel gear 47 at 1to 1 or direct drive. Reverse is obtained by engaging brake 61 to stopthe ring gear 60. Then the planetary gear 59 connected by carrier 63 tothe output gear 47 is driven by the sun gear 58 on the carrier element42. The intermediate and low planetary gear sets drive the sun gear 58to provide reverse drive. For a more complete description of thistransmission and showing of a suitable control system, reference is madeto the copending application and patents of Robert M. Tuck, SerialNumber 451,146, filed August 20, 1954, now Patent No. 2,899,846, PatentNo. 2,853,891 issued Sep tember 30, 1958, and Patent No. 2,884,806issued May 5, 1959.

The transmission output bevel gear 47 drives the bevel driven gear 67fixed on the cross drive shaft 68. A spur gear 70 mounted on the shaft68 drives the spur gear 71 to connect it to the brake cooling pump andoutput pump drive shaft 72. The cross drive shaft 68 extends across thevehicle and is connected by the support 76 to the ring gear 77 of thedouble differential. The ring gear meshes with planetary pinions 78mounted on a carrier 79 connected to the intermediate shaft 80. Theplanetary pinions 78 also mesh with a sun gear 83 which is connected bya short connecting sleeve to the large spur gear 85. The sun gears 83are the torque reaction members of double differential planetary gearsets, one being located on each side of the vehicle. The sun gears 83are interconnected by the spur gears 85 and a torque reaction drive. Thetorque reaction drive consists of a spur gear 86 which meshes with theleft hand gear 85 and is mounted on the torque reaction shaft 87. Theright hand sun gear 83 is connected to the right hand spur gear 85 whichmeshes with the idler gear 88 and a spur gear 89 fixed on the torquereaction shaft 87. The torque reaction shaft shown broken away in FIG. 1extends across the transmission above or below the drive gearing.

The steer clutch 92 has reactor plates connected through the gear 85 tothe reaction sun gear 83 and driving plates attached to the ring gear93. The right and left hand steer clutches 92 each have a ring gear 93which meshes with a spur gear 94. Both the right and left hand spurgears 94, which drive the respective steer clutches, are fixed to thesteer drive shaft 95. The steer drive shaft receives power from thetorque converter output shaft through the connecting bevel gear 97 whichdrives the bevel gear 98 of cluster 99. Cluster 99 also has the spurgear 100 which meshes with spur gear 101 on the steer shaft 95. Theflywheel 106 is rotatably supported on the steer shaft 95 and connectedthrough gear 107 to the reaction spur gear 85.

A Pitot tube governor can 108 of annular shape is mounted on the spurgear 101 which drives the steer shaft 95 and thus is driven inaccordance with the output speed of the torque converter. The Pitot tube109 has its opened end positioned in the can facing the fluid rotatingin the annular trough.

The intermediate output shaft 80 at each side of the vehicle isconnected to the final drive assembly which includes a vehicle brake 111and a planetary reduction gear 112. The shaft 80 drives the sun gear 113which drives the pinions 114 and carrier 115 connected to the propulsionmechanism at reduced speed. The ring gear 105 of the planetary gear setis fixed to the housing 117.

FIG. 2 shows in detail the left hand planetary gear set of the doubledifferential and the left hand steer clutch and servo motor which islocated at the left side of the transmission housing 116 within the leftsteer clutch housing 117. The cross drive shaft 68 is suitably supportedon the hearings in the transmission housing and has splined at its outerend the support 76 for the ring gear 77. The ring gear 77 meshes withplanet pinions 78 and which mesh with reaction sun gear 83. The planetpinions 78 are rotatably supported on the carrier 79 fixed on the innerend of the intermediate shaft 80. The reaction sun gear 83 is rotatablysupported by a disc 119 and the spur gear 85 is rotatably supported by adisc 120. The discs 119 and 120 are secured together by bolts 121 androtatably supported on the thrust bearing 122 on an inner cylindricalsleeve portion 124 of the housing 117. The reaction plates 127 of clutch92 are secured by suitable splines to a driven drum 128 which is alsoattached by the bolts 121 to the disc 119 and sun gear 83 and the disc120 and spur gear 85 and rotatably supported on the bearing 122. Thedriving discs 131 of clutch 92 are suitably splined to the outer drum132 which has a support 133 extending radially inwardly and Within theclutch drum 128 to rotatably support the drum 132 on bearing 134 onhousing sleeve 124. The outer race of thrust bearing 134 is secured tosupport 133 by a shoulder and snap ring to axially locate the support.

The clutch drum 132 has formed on its outer surface the spur gear 93which is connected by a spur gear 94 to the steer shaft 95. The sun gearsupport disc 119 and the spur gear support disc 120 and the clutchdriven ele ment 128 which is secured together by the bolt 121 aresecured to the bearing 122 by a split ring 136 fitting between the twodiscs and into a groove in the outer race of the bearing 122. Split ring138 in the outer surface of fixed sleeve 124 prevents movement bearings122 to the right. A spacer ring 139 is located between bearings 122 and134 so that the thrust on bearings 134 and 122 is transferred to thesnap ring 138 and housing sleeve 124. An annular clutch pressure plate141 is supported for axial movement within the drum support 133. Aplurality of posts 142 are fixed to the pressure plate 141 by suitablescrews and extend through apertures in the support 133 to preventrelative rotation of the pressure plate and outer drum. The posts 142are secured to the transfer ring 143 which is suitably secured byshoulders to the outer race of thrust bearing 144. A retraction spring146 consisting of a plurality of Belleville springs is located betweenthe transfer bearing 144 and the fixed bearing 134. The left end of thecasing 117 is formed to provide a cylinder 149 in which the piston 151axially reciprocates. The front face of piston 151 has an annular foot152 engaging the inner race of bearing 144 to transmit the actuatingforce through the transfer ring 143 to the clutch pressure plate 141.The cylinder 149 has an annular recess 155 located in the annular endwall of the cylinder. A valve sleeve 156 is fixed in an enlarged portionof the annular recess 155 and extends in an axial direction with respectto the piston. A hollow valve spool 157 which fits in the valve sleeve156 is mounted on a stud 158 suitably riveted to the piston 151. Thestud 158 extends axially from the rear face of the piston 151, throughthe central bore in the spool valve 157 and is headed to secure thespool valve in an axially fixed position with respect to the piston.There is sufficient clearance between the stud 148 and the bore in thespool valve 157 to permit sufficient flow of oil to prevent oil beingtrapped in the inner end of the valve sleeve 156. The valve spool 157has an annular recess 161 having a very small cross section area locatedadjacent the piston and an annular recess 162 of a substantially largercross sectional area located adjacent the free end of the spool. Thevalve sleeve 156 has a cooling oil inlet aperture or port 163 whichreceives fluid from the cooling oil passage 164. At diametricallyopposite sides of the valve, the valve sleeve 156 has an outlet apertureor port 166 which is connected by an outlet passage 167 to the passage168 between the housing sleeve 124 and the intermediate shaft 80. Whenthe piston is in its fully retracted position, as shown, the small areaannular passage 161 in the spool valve is aligned with the inlet port164 and the outlet port 166. The outlet port is also made sufficientlylarge so that it will drain the large annular passage .162. Oil suppliedby passage 167 will pass through the bearing 169 but is stopped by thesealing member 170. The oil will flow to the right through the space 168between the housing sleeve 124 and intermediate shaft 80 through thebearing 122 and radially outwardly to the aperture 130 to the drum 128.

The fluid or oil for the control and cooling systems shown in FIG. 3 issupplied from the transmission sump 190 by a pump 19:1 driven by theoutput shaft and pump 192 driven by the input shaft. The pumps arearranged in parallel and deliver the oil through a common supply passage194 to an oil filter 195 which discharges the filtered oil to atransmission control passage 197. A bypass valve 198 is provided betweenthe filter supply passage 194 and the transmission control passage 197to bypass theoil around the filter when the filter is clogged. Thetransmission control system which is supplied with fluid under pressureby the passage 197 may be a manual system as illustrated in Patent No.2,853,891, issued September 30, 1958, to Robert M. Tuck, or an automaticsystem as illustrated in Patent No. 2,884,806, issued May 5, 1959, toRobert M. Tuck. As in these systems, the

transmission control pressure in passage 197 is regulated by a regulatorvalve 199 which is located in a bore 201 located in a valve body orhousing portion. The transmission control pressure regulating valve .203has a small diameter land a at one end, a central land of intermediatediameter spaced from land a by a portion of reduced diameter and a largediameter land adjacent land b. The small land a fits in the smalldiameter portion of bore 201 between the control port 204 at the end andthe inlet port 205 connected to the transmission control passage 197.The land b has a diameter smaller than the large diameter bore portionof the bore 201 located below the port 205. The fluid outlet port 206 isconnected to the steer clutch supply passage 208. Valve 203 has a thirdland c fitting the bore 201 to close port 206-. The spring 209 ispositioned in the bore and resiliently urges the valve 203 upwardlyagainst the fluid pressure in passage 21 1 which is connected to port204 to supply a pressure to the top face of valve 203 when thetransmission is in intermediate and direct drive to reduce the pressurein passage 197. The aperture 212 in land a of valve 203 is connected byan axial bore 214 extending through the valve 203 to provide an exhaustconnected to the exhaust port 215.

The steer clutch regulator valve 221 has a valve element 223 located inand urged toward one end of a bore 222 in the valve housing by thespring 224. The port 226 at one end is connected to the steer passage208. A second port 227 is connected to the converter supply passage 229and a third port 230 is connected to the steer clutch passage 208. Thefourth port 231 at the spring abutment end of the bore 222 is connectedto a lubrication passage 232. The valve member 223 has a port 235located intermediate the ports 227 and 230 in the bore 222 when thevalve is in a closed position and providing a connection through acentral passage 236 in the valve 223 to the lubrication passage 232.

The converter pressure regulator valve 239 has a valve member 242slidably located in a bore 241 in the valve housing. The valve member242 which has a pair of spaced lands is urged by springs 243 toward theend port 244 connected to the converter input passage 229. The converteroutput passage 246 is connected to port 247 which is closed when thevalve is closed and connected between the lands to the outlet port 248located between the inlet port 247 and the control port 244 when thevalve is open. An exhaust port 249 permits oil which leaks past thepiston to exhaust to the sump.

The outlet port 248 of valve 239 is connected by passage 253 through acooler 254 to the cooler outlet passage 255. A by-pass valve 256 islocated between the cooler input passage 253 and cooler output passage255. Cooler output passage 255 delivers the oil to a filter 258 having abuilt-in by-pass valve 257 and an outlet connected to the lubricationpassage 232. A pressure in the lubricating passage 232 and the connectedsteer clutch cooling line 164 is maintained by a relief valve 259 havinga piston 260 which relieves excess pressure to a sump passage 261. Thelubricating line 232 also supplies oil to the Pitot tube governor can108 mounted for rotation on the steer shaft 95. Pitot tube 109 suppliesthe governor oil pressure proportional to the converter turbine 14 speedto the auto matic control mechanism.

The steer clutch control valve 262 consist of a valve 263 located in abore 264 for the left hand steer clutch and a valve 266 located in abore 267 for the right hand steer clutch. A headed control rod 271 issecured to one end of the valve 263. The rod 271 has slidably mountedthereon a control member 272 having an annular recess and a sleeve guidefor the springs 273 which hold the control member 272 against the headof the rod 271. The valve 266 has the same type of control rod 271,control member 272 and springs 273.

The steering control is actuated by a handle (not shown) located outsideof the valve housing which rotates the shaft 275 to rotate lever 276. Apin 277 shown as a circle of dotted lines, FIG. 3, is secured to eachend of lever 276 and extends radially into the annular groove at the endof each of the control members 272. A construction of this type isexplained in patent 2,689,488 issued to John E. Storer, Jr., and WilliamG. Livezey on September 21, 1954. A spring loaded detent 279 engages arecess in the collar on the shaft 275 to hold the valves in the neutralor straight forward drive position. When valve 263 is in the neutralposition, as shown in FIG. 3, the space between the lands 263a and b isconnected to the line 281 to the left hand steer clutch cylinder 149.Similarly the space between the lands a and b of the valve 266 is connected by a line 233 to the cylinder 149 of the right hand steer clutch.Valve 263 also has a bore 285 extending from a space between the lands aand b to the other end of the valve beyond the land 0. Land 0 has alarge diameter and is located in a large diameter portion of the bore264. Similarly valve 266 has a bore 286 connecting the space between thelands a and b to the end of the valve beyond the land c which is oflarger diameter and fits into a larger diameter portion of the bore 267.The steer clutch supply line 208 is connected to the valve bore 264 atport 288 and to bore 267 at port 289. On the other side of the steerclutch lines 281 and 283, the com mon exhaust port 292 is located inbores 264 and 267. The exhaust port 292 discharges the exhaust throughthe chamber 293 housing the valve control shaft 275 and associatedmechanism to exhaust 294. The chamber at the outer end of the land 263cis connected by a passage 296 to the chamber in the large portion ofport 267 on the valve side of the land 2660 to provide a reaction orfeel for the steering handle. Similarly the chamber on the valve side ofthe passage 2630 is connected by a line 297 to the chamber at theoutside face of the land 266s.

The torque converter provides a multiple ratio drive between the engineand the converter output shaft 16. The converter output shaft isconnected by the multiple ratio transmission providing three forwardspeed ratios and reverse to the transmission output bevel gear 47 whichdrives through the bevel gear 67 the transmission cross drive shaft 68.Cross drive shaft 68 is connected at each side of the vehicle to a ringgear 77 of a planetary gear set consisting of planetary piuions 7'8 anda carrier 79 mounted on the intermediate output shaft 80 and a torquereaction sun gear 83. The sun gears 83 of the planetary gear set on eachside of the vehicle are held to provide the torque reaction by a spurgear drive consisting of the gears 85 and 86 on one side and gears 85,88 and 89 on the other side of the vehicle with the final spur gears ofthe gear train on each side of the vehicle, that is, gears 86 and 89,interconnected by a transversely extending torque reaction shaft 87.This double differential drive arrangement provides both a reductiongear and a differential which i particularly adapted to be controlledfor steering the vehicle. When the vehicle is moving in a straight line,the sun gears 83 of both the right and the left planetary gear set ofthe double differential are stationary. During a turn, the sun gear inthe drive for the inside propulsion member will rotate backward toretard the inside propulsion member or track and the sun gear in thedrive for the outside propulsion member will rotate forward to advancethe outside propulsion member so that it can traverse the longer are inthe same time as the inside member traverses the shorter arc.

The spur gears 85 on each side of the vehicle which rotate with thetorque reaction sun gears are each connected by a steering clutch 92 toa live steering shaft which is driven through bevel gears 97 and 98 andspur gears 100 and 101 by the torque converter output shaft 16. Thesteer shaft 95 rotates in the proper direction so that when it isconnected through gear 94 and the steer clutch 92 that it will rotatethe sun gear backward and retard the associated propulsion member. Thus,if the left hand clutch is applied so that the steer shaft 95 transmitspower to reversely rotate the reaction sun gear 83 and retard the trackon the left side of the vehicle, the torque reaction shaft 87 andgearing will forwardly rotate the reaction sun gear 83 and advance thetrack on the right side of the vehicle and the vehicle will turn to theleft. A right turn is made when the right steer clutch is applied toreversely rotate the reaction sun gear 83 and retard the track on theright side of the vehicle and the cross shaft 87 will forwardly rotatethe sun gear 83 and advance the track on the left side of the vehicle.In order to reduce vibration and clutch chatter in the steeringassembly, a flywheel 106 is mounted to rotate about the live steer shaft95 and is geared to rotate with the reaction sun gears 83 in order toincrease the inertia of the double differential drive.

In the hydraulic control system illustrated in FIG. 3, the oil issupplied from the transmission sump 190 to output shaft driven pump 191and input shaft driven pump 192 arranged in parallel to supply pressureto the passage 194. The oil then passes through a sutiable filter 195which has a check valve 198 in by-passing relation connected to thefilter output passage 197. The passage 197 supplies fluid to thehydraulic gear ratio controls which, as indicated above, may be the sameas disclosed in the patents by Robert M. Tuck, Nos. 2,853,891 and2,884,806. The pressure regulator valve 199 is connected to the passage197 which operates on the unbalanced lands a and c to move the valve anddischarge fluid to port 206 into the steer clutch apply line 208.Further movement of valve member 203 will connect the transmissioncontrol supply passage 197, via port 205, through the port 212 in land aand bore 214 to the exhaust port 215 to provide a more rapid release offluid to reduce the pressure. It will be noted that the line 211supplies a pressure in the intermediate and high ranges of the automatictransmission to the space above the land a of valve 203 to reduce thepressure supplied to the transmission control mechanism in intermediateand high. This provides a high transmission control pressure in reverseand low ratios and a low pressure in intermediate and high ratios. Steerclutch pressure, which may be about pounds per square inch, enters port226 and acts on the end of the steer clutch pressure regulator valve221. If the pressure of steer clutch line 208 is excessive or above 100p.s.i., it will move the valve 223 to the right, compressing spring 224,and permit the fluid to enter port 227 and be supplied to the convertervia passage 229. If the flow of fluid to the converter does notsufficiently reduce the pressure, further movement of the valve permitsflow from passage 208 through the port 235 and the central bore of thevalve 223 to the lubricating line 232.

The converter pressure is regulated by the converter pressure regulatorvalve 239. The end face of valve 242 of. the converter pressureregulator valve 239 is acted upon by the converter input pressure 229and tends to move the valve 242 to the right to permit flow of fluidfrom the converter exhaust passage 246 to the outlet port 248 and coolersupply passage 253. The cooler supply passage 253 is connected viacooler 254 to the cooler outlet passage 255. Check valve 256 permits thecooler to be by-passed if an excessive pressure is generated in thecooler. The cooler output line 255 is connected to a filter 256 having abypass valve 257 which discharges the fluid into the lubrication andcooling line 232. The pressure level in lubrication line 232 ismaintained by a relief valve 259 which relieves excess pressure byopening the line to the sump.

The steering valves 262 are controlled by means of a manually operatedshaft 275 extending into chamber 293 which is connected by means of alever 276 having a pin and slot connection to the control member 272.The control member 272 is resiliently secured by spring 273 to the freeheaded end of the rod 271 secured to the end of valve 263 which controlsthe left hand steer clutch. The other end of the lever 276 actuated bythe hand control has a similar pin and slot connection to a similarcontrol member 272 which is mounted on a rod 271 and held at one end ofthe rod by a spring 273. The rod 271 is secured to one end of the valve266 which controls the right hand steer clutch. With the valves in thestraight forward position as shown in FIG. 3, the incoming fluid fromthe steer clutch supply line 208 is blocked at the ports 288 and 289. Inorder to make a left turn, the hand control shaft 275 is rotated to openleft clutch valve 263 by moving it to the right in FIG. 3 away from thehand control shaft. When the valve 263 moves to open, the space betweenthe land 263a and b connects the supply passage 208 to the left handsteer clutch control passage 281 while maintaining the exhaust port 292closed. The oil under pressure flowing between the lands 263a and b tothe steer clutch also enters the bore 285 in valve 263 and flows to thechamber in the large end of bore 264 and acts on the end face of land2630 to oppose the movement of the valve. Since the hand control shaftacts on the valve through springs 273 and the steer clutch pressureopposes movement of the valve 263, the valve regulates the pressure ofthe fluid supplied to the steer clutch in accordance with the handcontrol shaft position and the movement of the hand control shaft isopposed by a force proportional to the pressure in the steer clutchpassage 281. This force is called feel.

When the left clutch valve 263 is moved into the apply position, theright clutch valve 266 is moved out to the exhaust position and connectsthe right clutch servo to exhaust port 292. The left clutch applypressure in the end chamber of bore 264 acting on the end face of land2630 also is connected by passage 296- to act on the annular face ofland 266a or the unbalanced are-a between lands 266b and c to increasethe feel force. Since the force on the unbalanced area of lands 266b andc is transmitted directly by the rod 271 to the hand control shaft 275,the valve 266 controlling the exhaust does not regulate the pressure.The right clutch pressure from passage 283 can act on the end face ofland 2660 and if it is excessive move the valve to open or to increasethe opening of the exhaust port 292. Thus, springs 273 limit the clutchapply pressure.

A right turn is made by moving the valves in a direction opposite to theabove described movement for a left turn. For a right turn, the valve266 is moved in the 'bore 267 to connect the pressure supply passage 208to the right clutch supply passage 283 and to the bore 286 in valve 266to the chamber at the end of valve bore 267 to act on the end face ofland 2660. The pressure fluid acting on the end face of land 266copposes the valve apply force of hand control shaft 275 which istransmitted through springs 273 and thus regulates the pressure in rightclutch apply passage 283 and provides a feel force acting on the handle.This pressure force is also connected by passage 297 to the unbalancedarea between lands 263k and c to add an additional feel force acting onshaft 275.

The right clutch apply passage 283 and the left clutch apply passage 281are connected to the cylinders 149 of the servo motor actuating therespective steer clutches 127131. The steer clutch cooling passage 164is connected to the lubricating passage 232 and supplies oil to thespool valve 157. The spool valve 157 for each clutch transmits a smallquantity of oil when the piston 151 is retracted to disengage the clutchand transmits a large quantity of oil when the piston 1 is advanced toengage the clutch. The fixed piston 151 and valve 157 move together andactuate the clutch pressure plate 14-1 through a thrust bearing 144 anda transfer ring 148.

It will be understood that the above description of a preferredembodiment of the invention is illustrative of the invention and thatmodifications may be made within the scope of the appended claims.

I claim:

1. In a steering control system, a right clutch, a left clutch, a servomotor to operate each clutch, a source of fluid, a pair of clutchcontrol valves, each valve being movable to an apply position to connectsaid source to one of said servo motors, to a release positionconnecting the other of said servo motors to exhaust and to a neutralposition disconnecting said servo motors from said source and saidexhaust, hand control means moving one of said valves in one directionto move said one valve from the neutral to the apply position andsimultaneously engage the other of said valves to move said other valveto the release position, said valves in said clutch apply positionapplying the pressure in said servo to oppose the movement of the valvetoward the apply position and applying the same pressure to the othervalve when in the release position to oppose the movement of the othervalve to the release position, and means controlled by said servo motorto supply a large volume of cooling fluid to said clutches when engagedand to supply a small volume of lubricating fluid to said clutches whendisengaged.

2. The invention defined in claim 1, said hand control means including aspring to transmit the control force to move said valves in said onedirection and including rigid means to transmit the control force tomove said valves in said other direction.

3. In a steering control system, a right clutch, a left 10 clutch, aservo motor to operate each clutch, a source of fluid, a pair of clutchcontrol valves, each valve being movable to an apply position to connectsaid source to one of said servo motors, to a release positionconnecting the other of said servo motors to exhaust and to a neutralposition disconnecting said servo motor from said source and from saidexhaust, a control element slidably mounted on each valve, a fixedabutment limiting movement of said control elements in one directionwith respect .to said valve, resilient means limiting movement of saidcontrol elements in the other direction with respect to said valve, handcontrol means moving one of said control elements and one valve in saidother direction to move said one valve from the neutral to the applyposition and simultaneously engaging the other of said control elementsto move said other control element and the other valve in said onedirection to move the valve through said resilient means from theneutralposition to the release position, said valves in said clutchapply position applying the pressure in said servo to oppose themovement of the valve in the apply position and to regulate the clutchapply pressure and applying the same pressure to the other valve in therelease position to oppose the movement of the other valve to therelease position.

4. A clutch assembly, a housing, a driving element, a driven element,clutch means connecting and disconnecting said driving element and saiddriven element, a cylinder and a valve bore on said housing, a pistonslidably mounted in said cylinder, means connecting said piston to saidclutch means to actuate said clutch means to connect and disconnect saidclutch means, a valve mounted to move with said piston and slidable insaid valve bore, a source of cooling fluid, said valve transmitting asmall quantity of cooling fluid from said source to said clutch meanswhen the clutch is disengaged and said valve transmitting a largequantity of cooling fluid fromsaid source to said clutch when the clutchis engaged.

5. The invention defined in claim 4 and said valve bore being located insaid cylinder, means securing said valve to said piston to axially fixsaid valve to said piston and to permit limited lateral movement tocorrect for mislocation and misalignment of said valve bore andcylinder.

6. In a steering drive assembly, a housing having a support sleeve, acontrolled element, a direct controlling element, at clutchedcontrolling element, an inner clutch drum located externally of saidsupport sleeve, an annular backing plate fixed to said inner clutch drumadjacent one end, extending outwardly from said inner clutch drum andconnected to said direct controlling element, first bearing meansaxially and rotatably supporting said inner clutch drum, backing plateand direct controlling element on said housing, an outer clutch drumhaving a hub with an aperture, second bearing means axially androtatably supporting said hub and outer clutch drum on said houslng, aplurality of clutch plates with one plate secured to the inner clutchdrum and another plate secured to the said outer clutch drum, a clutchpressure plate adjacent the other end of said inner clutch drum engagingsaid clutch plates, said clutch plates being mounted for axial movementbetween said inner and outer drums to engage and disengage said clutchplates, said housing having a cylinder, a piston slida bly andnonrotatably mounted in said cylinder, means including a transferbearing connected to said piston, extending through said aperture insaid hub and connected to said clutch pressure plate to permit relativerotation of said piston and clutch pressure plate, and reaction springmeans located between said transfer bearing means and said housing toreturn said piston. I

7. In a drive assembly, a housing having a support sleeve, a controlledelement, a direct controlling element, a clutched controlling element,an inner. clutch drum located externally of said support sleeve, anannular backing plate fixed to said inner clutch drum adjacent one end,extending outwardly from said inner clutch drum and connected to saiddirect controlling element, first bearing means axially and rotatablysupporting said inner clutch drum, backing plate and direct controllingelement on said housing, an outer clutch drum having a hub with anaperture, second bearing means axially and rotatably supporting said huband outer clutch drum on said housing, a plurality of clutch plates withone plate secured to the inner clutch drum and another plate secured tothe said outer clutch drum, a clutch pressure plate adjacent the otherend of said inner clutch drum engaging said clutch plates, said clutchplates being mounted for axial movement between said inner and outerdrums to engage and disengage said clutch plates, said housing having acylinder, a piston slidably and nonrotatably mounted in said cylinder,means including a transfer bearing connected to said piston, extendingthrough said aperture in said hub and connected to said clutch pressureplate to permit relative rotation of said piston and clutch pressureplate, reaction spring means located between said transfer bearing meansand said housing to return said piston, and said piston including valvemeans to control the supply of lubricating oil to said clutch plates.

8. In a drive assembly, a housing having a support sleeve, a controlledelement, a direct controlling element, a clutched controlling element,an inner clutch drum located externally of said support sleeve, anannular backing plate fixed to said inner clutch drum adjacent one end,extending outwardly from said inner clutch drum and connected to saiddirect controlling element, first bearing means axially and rotatablysupporting said inner clutch drum, backing plate and direct controllingelement on said housing, an outer clutch drum having a hub with anaperture, second bearing means axially and rotatably supporting said huband outer clutch drum on said housing, a plurality of clutch plates withone plate secured to the inner clutch drum and another plate secured tothe said outer clutch drum, a clutch pressure plate adjacent the otherend of said inner clutch drum engaging said clutch plates, said clutchplates being mounted for axial movement between said inner and outerdrums to engage and disengage said clutch plates, said housing having acylinder, a piston slidably and nonrotatably mounted in said cylinder,means including a transfer bearing connected to said piston extendingthrough said aperture in said hub and connected to said clutch pressureplate to permit relative rotation of said piston and clutch pressureplate.

9. In a drive assembly, a housing having a support sleeve, :1 controlledelement, a direct controlling element,

a clutched controlling element, an inner clutch drum located externallyof said support sleeve, as annular backing plate fixed to said innerclutch drum adjacent one end, extending outwardly from said inner clutchdrum and connected to said direct controlling element, first bearingmeans axially and rotatably supporting said inner clutch drum, backingplate and direct controlling element on said housing, an outer clutchdrum having a hub, second bearing means axially and rotatably supportingsaid hub and outer clutch drum on said housing, a plurality of clutchplates with one plate secured to the inner clutch drum and another platesecured to the said outer clutch drum, and a clutch pressure plateadjacent the other end of said inner clutch drum engaging said clutchplates, said clutch plates being mounted for axial movement between saidinner and outer drums to engage and disengage said clutch plates.

10. A clutch assembly, a housing, a driving element, a driven element,clutch means having a movable member connecting and disconnecting saiddriving element and said driven element, a cylinder and a valve bore onsaid housing, a piston slidably mounted in said cylinder, meansconnecting said cylinder to said clutch means to actuate said clutchmeans to connect and disconnect said clutch means, a valve mounted tomove with said movable 12 member and slidable in said valve bore, asource of cooling fluid, said valve transmitting a small quantity ofcooling fluid from said source to said clutch means when the clutch isdisengaged and said valve transmitting a large quantity of cooling fluidfrom said source to said clutch when the clutch is engaged.

11. A clutch assembly, a housing, a driving element, a driven element,clutch means connecting and disconnecting said driving element and saiddriven element, a cylinder in said housing, a valve bore in said housingextending from one end of said cylinder coaxially of said cylinder, apiston slidably mounted in said cylinder, means connecting said cylinderto said clutch means to actuate said clutch means to connect anddisconnect said clutch means, a valve mounted on said piston to movewith said piston and slidable in said valve bore, a source of coolingfluid, said valve transmitting a small quantity of cooling fluid fromsaid source to said clutch means when the clutch is disengaged and saidvalve transmitting a large quantity of cooling fluid from said source tosaid clutch when the clutch is engaged.

12. A clutch assembly, a housing, a driving element, a driven element,clutch means connecting and disconnecting said driving element and saiddriven element, said clutch means being rotatable when connecting, acylinder in said housing, a valve bore in said housing extending fromone end of said cylinder coaxially of said cylinder, a piston axiallyslidably and non-rotatably mounted in said cylinder, bearing meanspermitting relative rotary movement connecting said cylinder to saidclutch means for common axial movement to actuate said clutch means toconnect and disconnect said clutch means, a valve mounted on said pistonto move axially with said piston and slidable in said valve bore, asource of cooling fluid, said valve transmitting a small quantity ofcooling fluid from said source to said clutch means when the clutch isdisengaged and said valve transmitting a large quantity of cooling fluidfrom said source to said clutch when the clutch is engaged.

13. In a steering control system, a right clutch, a left clutch, a motorto operate each clutch, a source of fluid, a pair of clutch controlvalves, each valve being movable to an apply position to connect saidsource to one of said motors, to a release position connecting said onemotor to exhaust and to a neutral position disconnecting said one motorfrom said source, control means connected to said valves to move eithervalve to the apply position and the other valve to the release position,and said valves in said clutch apply position applying the pressure inthe motor being applied to oppose the movement of the valve toward theapply position and applying the same pressure to the other valve when inthe release position to oppose the movement of the other valve to therelease position.

14. The invention defined in claim 13 and said control means having aconnection to each valve to resiliently engage the valve for movement inan apply direction and rigidly engage the valve for movement in arelease direction.

15. In a drive control system, a first drive control means, a seconddrive control means, a motor to operate each drive control means, asource of fluid, a pair of control valves, each valve being movable toan apply position to connect said source to one of said motors, to arelease position connecting said one motor to exhaust and to a neutralposition disconnecting said one motor from said source, control meansconnected to said valves to move either valve to the apply position andthe other valve to the release position, and said valves in said applyposition applying the pressure in the motor being applied to oppose themovement of the valve toward the apply position and applying the samepressure to the other valve when in the release position to oppose themovement of the other valve to the release position.

1 6. The invention defined in claim 15 and said control means having aconnection to each valve to resiliently engage the valve for movement inan apply direction and rigidly engage the valve for movement in arelease direction.

17. A drive assembly, a housing, a driving element, a driven element,drive means connecting and disconnecting said driving element and saiddriven element, a cylinder and a valve bore on said housing, pistonmeans slidably mounted in said cylinder, means connecting said pistonmeans to said drive means to actuate said drive means to connect anddisconnect said drive means, a valve mounted to move with said pistonmeans and slidable in said valve bore, a source of cooling fluid, saidvalve transmitting a small quantity of cooling fluid from said source tosaid drive means when said drive means is disengaged and said valvetransmitting a large quantity of cooling fluid from said source to saidclutch when said drive means is engaged.

18. The invention defined in claim 17 and said valve bore being locatedin said cylinder, means securing said valve to said piston means toaxially fix said valve to said piston and to permit limited lateralmovement to correct for mislocation and misalignment of said valve boreand cylinder.

14 19'. The invention defined in claim 17 and said valve bore extendingcoaxial with an axis of movement of said piston means and opening intosaid cylinder and said valve being mounted on said piston means formovement with said piston means and extending into said bore.

References Cited in the file of this patent UNITED STATES PATENTS1,953,568 Rose Apr. 3, 1934 2,301,099 Upp Nov. 3, 1942 2,329,742 Bush eta1 Sept. 21, 1943 2,426,063 Stevens Aug. 19, 1947 2,588,937 Ringman Mar.11, 1952 2,775,331 Peterson Dec. 25, 1956 2,806,567 Bonquet Sept. 17,1957 2,820,372 Edge et a1 Jan. 21, 1958 2,869,701 Yokel Jan. 20, 19592,880,586 Lincoln Apr. 7, 1959 FOREIGN PATENTS 56,771 France July 30,1952 (1st. addition to No. 929,278)

:UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,3,059,,746 October 23 1962 1 Howard W. Christenson It is herebycertified that error appears in the above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

Column l line 20, strike out "The cross drive shaftfl'g column 5, line10 for "148" read 158 column 6, lines 66 and 67, for "large", eachoccurrence read larger Signed and sealed this 2nd day of April 1963,

(SEAL) Attest:

ESTON Go JOHNSON DAVID L. LADD Attesting Officer Commissioner of Patents

